Let F n and L n be the nth Fibonacci and Lucas number, respectively. The order of appearance is defined as the smallest natural number k such that n divides F k and denoted by z(n). In this paper, we give explicit formulas for the terms z (F a F b) , z (L a L b) , z (F a L b) and z (F n F n + p F n + 2 p) with p ≥ 3 prime.